ST. HELENA (CBS SF) – Temperatures have dropped and humidity has risen, giving an edge up to firefighters battling a vegetation fire in Butts Canyon that has rapidly spread to 3,200 acres. The fire, just west of Lake Berryessa, was 30 percent suppressed as of 5:15 a.m. Wednesday after fire crews built containment lines through the night. Evacuations remain in effect for residents in the 180 homes of the Berryessa Estates subdivision in the Pope Valley Area as well as on Snell Valley Road to the Lake County line.

Tony Sarto, a park aide at Bothe-Napa Valley State Park, located about 5 miles north of St. Helena and at least 7 miles south of where fire is burning, said that from the park he could see smoke billowing up above the hills late Tuesday evening. “It looks like a volcano erupted,” Sarto said. Sarto said he saw a large cloud of smoke pushing up over the hills as he drove to the park from Santa Rosa Tuesday afternoon.

Map of wildfire in Napa County on July 1, 2014. (CBS)

Sarto said that while the fire is certainly significant, Bothe-Napa is not in the danger zone and that their operations are not interrupted. While firefighters battled the blaze overnight, many campers are spending the night at the Bothe-Napa campgrounds and are even permitted to have campfires in designated areas. Sarto said that while the park remains on high alert as firefighters work to stop the fire from spreading to more land, the park staff is preparing for the upcoming Fourth of July holiday weekend, and therefore no park rangers were scheduled to work until the park reopens at 8 a.m. on Wednesday. According to witnesses, flames were jumping 20 to 30 feet high. Smoke was visible in the Sacramento suburb of El Dorado Hills, more than 100 miles away. More On The Napa Co. Wildfire:

ut 20 miles from the upper end of the Napa Valley. The Red Cross set up a shelter for evacuated residents Tuesday afternoon providing cots for adults and kennels for pets at Pope Valley School in Pope Valley and the Middletown High School in Lake County. At least five structures, including one home, have been damaged since the fire started around 12:08 p.m. Tuesday in the 7800 block of Butts Canyon Road, McCambridge said. Firefighters from around the area are assisting, including those from the City of Napa, St. Helena and the Lake County and Napa County fire departments, the California Highway Patrol and the Napa County Sheriff’s Office.FIRE DATA: